How can I tell how much space is needed when installing say science-mathematics with # apt-get install science-mathematics

If I do
# apt-cache show science-mathematics

it says, Installed-Size: 60; clearly this is wrong even if it was kilobytes.

So my questions are,
why is it wrong?
And,
How would you find out before installing?

Is there another way? as I know I could kick off an install and then I'm prompted for yes or no, but I would like to know if its possible before getting that far.

Cheers,

There's just guesstimates once your disk gets close to full.

I use 'df -h', and that gives you a general idea of how much space is left on a partition. Bear in mind a portion of the disk is left for root, so a user runs out of space when the disk is less than full.

Bear in mind also that logs need to be written. As you get close to full, delete a bit to make space, etc, the amount of fragmentation goes up enormously so disk speeds slow.

An IT manager friend of mine had a rule of thumb of minimum 10% free disk space to keep windows from crashing. Not a bad one. It's the time to start doing something.

If things get desperate, you can always pull a 'rm -rf' on /usr/share/doc, /usr/doc,

thanks for the response. I know all about disk space and thoughtless data retention policies. I just wanted a quick way of finding out how much space a package would take up when installed. it looks like the installed size figure is pretty useless. I guess the answer is to start an install and answer no if there is not enough space. I'm using LVM so I can grow and shrink files stems if needed. I think I am looking at meta packages, which might explain it. Also fs type and block size makes it a guesstimate only. it just puzzled me why use an installed-size value that's really no good.

Cheers.

Most of the packages in distros are broken up into fairly small pieces.

I am inclined to use slackware, which has libs, includes, binaries, documentation & extras all in one package.

You're right it's a meta-package, it exists only to pull in other packages, hence the small installed size. When you install it through apt-get you are shown how much all the packages you are about to install will take up (or free) in MB terms.

1 members found this post helpful.

Hi all,
Of course I should have remembered from my LPIC-1 exam.
use it or lose it I guess.

answer is
# apt-cache -s <packagename>

-s for simulate.

Shows what will be installed and how much space is required.
Extremely useful.

Regards,